Modelling the role of amelioration and drug lords on drug epidemics and the impact of substance abuse on the dynamics of HIV/AIDS

Njagarah, Hatson John Boscoh (2011-12)

Thesis (MSc)--Stellenbosch University, 2011.

Thesis

ENGLISH ABSTRACT: Substance abuse is an imminent danger on the health of both substance users and nonusers. In general, abuse of psychoactive substances is associated with high risk behaviour, mortality and morbidity. The drug use cycle involves inextricably intertwined variants such as production, trading and usage of both licit and illicit addictive substances. The dynamics of substance use involve initiation, addiction, rehabilitation/treatment and quitting/ recovery. In response to supply and abuse of monster drugs, control strategies such as law enforcement and rehabilitation have been stepped up to reduce access to drugs by targeting drug kingpins and harm reduction respectively. In this thesis, we model the factors affecting the prevalence of substance abuse, the effect of drug lords on the prevalence of substance abuse, and the impact of substance abuse on the prevalence of HIV/AIDS. We formulate mathematical models based on systems of autonomous differential equations describing the dynamics of the sub- populations involved in the drug using cycle. We examine the effects of amelioration, rehabilitation/treatment and re- initiation on the prevalence of substance abuse. Our results suggest that, recruitment into rehabilitation and amelioration in the presence of quitting for light users reduce the prevalence of substance abuse; re-initiation and amelioration without quitting for light users increase the prevalence of substance abuse. Our assessment of the impact of drug lords and the effect of law enforcement on drug epidemics shows that, the presence of drug lords seriously constraints the efforts to reduce substance abuse since they increase access to drugs. However, law enforcement if stepped up in response to the population of drug lords, greatly reduces the prevalence of substance abuse. Given the associated influence of drugs on high risky behaviour, as a cofactor for sexually transmitted infections, we assess the influence of substance abuse on the prevalence of Human Immunodeficiency Virus (HIV). Our results show that dissemination of information regarding HIV and drug use reduces HIV prevalence whereas, there is faster spread of the epidemic and high prevalence with increased sexual contact.

AFRIKAANSE OPSOMMING: Dwelmmisbruik is ’n dreigende gevaar vir die gesondheid van beide dwelm gebruikers en nie-gebruikers. In die algemeen, word die misbruik van psigoaktiewe dwelms verbind met hoë risiko gedrag, mortaliteit en morbiditeit. Die dwelmgebruikskringloop behels onlosmaaklik vervlegde variante soos vervaardiging, handel en gebruik van beide wettige en onwettige verslawende middels. Die dinamika van dwelms behels aanvang, verslawing, rehabilitasie/ behandeling en staking/herstel. In reaksie op die misbruik en verskaffing van monster dwelms, is beheer strategieë soos wetstoepassing en rehabilitasie verskerp, om die toegang tot dwelms te verminder, deur onderskeidelik te fokus op dwelmspilfigure en skadebeperking. Die belangrikste doel van hierdie verhandeling is om die faktore te modelleer wat die voorkoms van dwelmmisbruik beïnvloed, die uitwerking van dwelmbase op die voorkoms van dwelmmisbruik, en die trefkrag van dwelmmisbruik op die voorkoms van MIV / VIGS. Ons formuleer wiskundige modelle gegrond op stelsels van outonome differensiaalvergelykings, wat die dinamika beskryf van die sub-bevolkinge wat in die dwelmgebruikskringloop betrokke is. Ons ondersoek die effekte van verbetering, rehabilitasie/behandeling en heraanvang op die voorkoms van dwelmmisbruik. Ons resultate dui dat, werwing tot rehabilitasie en verbetering in die teenwoordigheid van stakende tydelike verbruikers, die voorkoms van dwelmmisbruik verminder; heraanvang en verbetering sonder dat tydelike verbruikers staak, verhoog die voorkoms van dwelmmisbruik. Ons raming van die invloed van dwelmbase en die uitwerking van wetstoepassing op dwelm-epidemies toon dat, die teenwoordigheid van dwelmbase belemmer grotendeels die pogings om dwelmmisbruik te verminder, aangesien hulle toegang tot dwelms verhoog. Nietemin, as die wetstoepassing verskerp word in reaksie op die dwelmbaasbevolking, word die voorkoms van dwelmmisbruik aansienlik verminder. Gegewe die gepaardgaande invloed van dwelms op hoë risiko gedrag as ’n kofaktor vir seksueel oordraagbare infeksies, beraam ons die invloed van dwelmmisbruik op die voorkoms van die Menslike Immunogebreksvirus (MIV). Ons resultate toon dat inligtingverspreiding rakende MIV en dwelmgebruik, MIV-voorkoms verlaag, terwyl daar ’n vinniger verspreiding van die epidemie en hoë voorkoms is, met verhoogde seksuele kontak.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/17935
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